Design and Development of an Automatic Solar Charge Controller

Abstract:

As the sources of conventional energy deplete day by day, resorting to alternative sources of
energy like solar and wind energy has become essential of the hour. Solar-powered lighting
systems are readily available in rural as well as urban areas. These include solar lanterns, solar
home lighting systems, solar street lights, solar garden lights and solar power packs. All of them
consist of four components: solar photovoltaic module, rechargeable battery, charge controller
and load. In the solar-powered lighting system, the solar charge controller plays an important
role as the battery’s overall life depends mainly on it. In this point of view, this project presents
designing a Solar Charge Controller for the Solar Battery Charging Station with the function to
disconnect and reconnect battery and load during battery over charging or discharging. Instead of
using readily available microcontroller board (Eg. Arduino), here Arduino microcontroller
(Atmega328) has been used to make the system cost-effective. The source code for the Arduino
microcontroller is written in Arduino software. Furthermore, to ensure the full charge and to
avoid over discharge the SOC of the battery has been properly determined by sensing the
terminal voltage of the battery and the charging or discharging current. Normal charge controller
has four set-points which are fixed, but here the set-points will be automatically adjusted
depending on the level of charging and discharging current. As a current sensor ACS712 hall
current sensor has been used. The system has been simulated and practically implemented.
Performance study of the system shows that it works properly within the range 10A maximum.

Description:

This thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Electronics and Telecommunication Engineering of East West University, Dhaka, Bangladesh